Core sampling is typically employed to allow geological surveying of the ground for the purposes of exploration and/or mining development. Analysis of the composition of the core sample provides information of the geological structure and composition of the surrounding ground. In order to maximize the usefulness of this information it is necessary to have knowledge of the orientation of the core sample relative to the ground from which it is cut.
Applicant has developed several core orientation devices which are in current commercial use. One device is known as the EZY-MARK system and is described in Applicant's international application number WO 2005/078232. The EZY-MARK system includes an orientation head which houses a plurality of pins used to locate profile points on a face of the core being cut. One or more rubber bands or O-rings are seated about the head which hold the pins in place in the absence of an axial force. When the orientation tool is lowered on to a toe of a hole, which forms a face of the core being cut, the pins slide into the head against the force applied by the O-rings to provide reference points that correlate to points on the core face. Once the core has been extracted, it can be aligned with the orientation tool by matching the points of the pins with the core face to enable orientation of the core. The core can then be marked with a pencil or other indelible marker at a location corresponding to the gravitational lowest point on the core.